code: def generate_empty() -> DataFrame:
      return DataFrame(index=[0, 1, 2, 3, 4, 5, 6, 7, 8])
  
imports: import copy
  import numpy
  import pandas
  import pytest
  from pandas import DataFrame, Series
  from autogluon.common.features.feature_metadata import FeatureMetadata
  from autogluon.features.generators import AbstractFeatureGenerator
label_desc: Use image node_id 1 for calling the DataHelper obj's underlying member method code with example usage: obj.generate_empty() and returns: DataFrame